Sprinkler valve actuating device



7 r UUUlUlI nuu y 0, 1944. H. N. RIDER 2,349,883

SPRINKLER VALVE ACTUATING DEVICE Filed Oct. 19, 1942 4 Sheets-Sheet 1 Bnventor Gttorneg May 30, 1944. R|DER 2,349,883

SPRINKLER VALVE ACTUA'IING DEVICE Filed on. 19, 1942 4 Sheets-Sheet 2 'llllllllllll Illllllll.

[V1 [/11 III.

Summer (mm-m May 30, 1944. H. N. RIDER SPRINKLER VALVE ACTUATING DEVICE 4 Sheets-Sheet 3 Filed Oct. 19, 1942 III Gttorneg Patented May 30, 1944 SPRINKLER VALVE ACTUATIN G DEVICE Harry N. Rider, Youngstown, Ohio, assignor to Automatic Sprinkler Company of America, Youngstown, Ohio, a corporation of Delaware Application October 19, 1942, Serial No. 462,631

.. 8 Claims.

This invention relates to a valve actuating device and is intended for use primarily with sprinkler systems of the deluge type.

The principal object of the invention is the provision of an arrangement of heat actuated devices capable of being installed in enclosures such as tanks in which infiammables are present and in which varying pressures in excess of atmospheric are likely to be encountered.

A further object of the invention is the provision of a novel grouping of heat actuated devices forming a heat detecting unit capable of originating a pneumatic impulse which in turn may be employed to actuate a deluge sprinkler system control valve.

A further object of the invention is the provision of a heat actuated device assembly incorporating a rate of rise pressure generating heat actuated device and a fixed temperature fusible element controlled pressure relieving device each of which is capable of independent operation while providing in combination a heat detecting assembly positive in operation adapted for installation in tank-like enclosures.

A still further object of the invention is the provision of a heat detecting assembly of heat actuated devices adapted for positioning within a tank like enclosure through a single relatively small opening in the said tank-like enclosure.

The sprinkler valve actuating device shown and described herein has been designed to enable the positive detection of fire or conditions likely to result in fire when installed in tank like enclosures which may or may not confine pressures in excess of or below atmospheric and which are adapted to receive, retain or transfer highly inflammable materials such as solvents, etc. As installed in solvent recovery tanks used in the manufacture of explosives, the device of the invention is located within the tank-like enclosure and serves to actuate a deluge valve of a deluge sprinkler system, the fiuid delivering portions of which are also located within the solvent recovery tank. Adaptions of the invention are also capable of installation in tank-like enclosures in which normal or below normal atmospheric pressure is present.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

Figure l is a schematic illustration of a solvent recovery tank showing the general location of the device of the invention as installed therein together with fluid delivering portions of the deluge sprinkler system subject to actuation thereby.

Figure 2 is a cross sectional side elevation of a portion of the device of the invention.

Figure 3 is a cross sectional side elevation of a portion of the sprinkler valve control device comprising the pneumatically operated valve actuating mechanism.

Figure 4 is a cross sectional side elevation of the fixed temperature fusible element pressure relieving portion of the heat actuated device of the invention.

Figure 5 is a side elevation of a pressure generating heat actuated device which forms a portion of the valve actuating device of the invention.

Figure 6 is a side elevation of a modified form of the fixed temperature fusible element pressure relieving portion of the device of the invention showing the same installed in a material conveying duct.

Figure 7 is a cross sectional side elevation oi a modification of the device illustrated in Figure 1 of the drawings.

By referring to Figure 1 of the drawings, it will be seen that a solvent recovery tank In or similar enclosure is illustrated which is adapted to contain highly inflammable and explosive ma terials. The tank l0 has a false top and a false bottom therein which are customary in such tanks. Inlet and outlet openings of the tank are indicated by the numerals II and I2, respectively, and the discharge portion of a deluge sprinkler system is indicated by the numeral 13. In order that fire extinguishing fluid may be discharged in adequate volume from the deluge sprinkler system l3 upon the rapid rise of temperature or outbreak of fire in the enclosure of the tank l0, sensitive heat actuated devices are located within the enclosure and are indicated by the numerals I4 and I5, respectively. The heat actuated device it comprises, as is best illustrated in Figure 4 of the drawings, a fixed temperature fusible element pressure relieving device. The heat actuated device indicated by the numeral I5 i best illustrated in Figure 5 of the drawings and comprises a pressure generating device.

Both the pressure relieving and pressure generating devices are assembled so as to form a dual acting heat detecting unit or assembly and are positioned within the tank-like enclosure III by means of a suitable connecting device best illustrated in Figure 2 of the drawings, the device being capahle of carrying all the connecting conduits through a single opening in the tanklike enclosure l and serving to seal the opening as well. In Figure l, the opening and the sealing means are generally indicated by the numeral IS. The actuating mechanism of a fluid control valve controlling the entrance of fire extinguishing fluid to the fluid delivering portions I3 of the deluge sprinkler system is indicated in Figure 1 by the numeral l1 and an exhaust to atmosphere is generally indicated by the numeral I8. In Figure 2 the specific exhaust to atmosphere comprises the L 31.

Still referring to Figure 1 of the drawings, it will be observed that upon the outbreak of fire or conditions likely to result in a fir or explosion within the tank-like enclosure H], the heat actuating devices I4 and I5, being located within the enclosure, detect the abnormal conditions and serve to actuate the actuating mechanism l! which in turn directly causes the opening of the deluge valve controlling th fluid supply of the deluge sprinkler system. The deluge valve itself is not shown other than in Figure l or described herein as the same is well known in the art.

By referring to Figure 3 of the drawings, a cross sectional side elevation of the valve actuating mechanism ll may be seen. In Figure 3 a sealed box-like enclosure indicated by the numeral ll, serves as a housing for a diaphragm case l9 enclosing a diaphragm ISA. A pin 20 is loosely and movably positioned in an opening of the diaphragm case l9 and so arranged that one end rests against the diaphragm l9A while the other end thereof extends outwardly from the said diaphragm case l9 and is adapted to engage a restraining element 2| which in turn is pivoted to a portion of the housing l! by means of a pivot 22. Positioned beneath one end of the said restraining element 2| there is a tiltable latch member 23 which is also pivoted to the housin I! by means of a pivot 24. An upturned end 25 formed on the tiltable latch member 23 serves to release a system of levers (not shown) which in turn permit a keeper 26 pivoted to the housing I! by means of a pivot 21 to revolve partly about the pivot, thus causing a projecting finger 28 to move downwardly. The projecting finger 23 forms a part of the keeper 2B and extends outwardly through an opening in the housing I! and is provided with a flexible seal 29 thereabout. The deluge valve which controls the supply of fluid to the fluid delivering portions l3 of the deluge sprinkler depends solely for actuation, upon the movement or the tiltable latch member 23 as in response to the movement of the diaphragm I9A which results in the pivoting of the keeper 25 about the pivot 21. This actuating mechanism generally indicated by the numeral I! and illustrated in Figure 3 as being enclosed in the housing I1, is set forth in complete detail and forms a part of U. S. Patent No. 2,099,069 of November 16, 1937 to E. A. Lowe et al. on Fire extinguishing and alarm apparatus and the same is therefore known in the art and does not constitute a part of the present invention.

By referring to Figure 2 of the drawings, a cross sectional side elevation of the mounting and inter-communication portions of the sprinkler valve actuating device may be seen, this portion of the invention being generally indicated in Figure 1 of the drawings by the numeral Hi. In

Figure 2, a vertical wall of the tank-like enclosure I0 is shown with the opening through which the device of the invention passes indicated by the numeral [6. A nipple 30 is welded in the opening and suitable re-enforcing members are provided and are indicated by the numeral 3|, the re-enforcing members 3| being located one on each side of the tank wall Ill. The re-enforcing members 3| and the nipple 30 form an air tight passageway through the tank wall l0.

Positioned on the outermost end of the nipple 30 there is a fitting 32 which establishes communication with the nipple 30 and with a communicating tube 33, an adapter 34 and a plug and connector 35. The communicating tube 33 communicates directly with the enclosure I! heretofore described, air pressure in excess of atmospheric, established by suitable means, within the enclosure 11, and which may be introduced thereinto through an opening I LA, will communicate directly with the interior of the fitting 32 as well as the interior of the nipple 30 and the other devices in communication therewith hereinaiter described.

The adapter 34 forms in effect a closure for the interior of the fitting 32 and serves to form a seal about a section of air tubing 36 which in turn extends inwardly through the adapter 34 as well as the fitting 32 and the nipple 3D and passes through a fitting 4!] inside the tank-like enclosure l0 and communicates with a fixed temperature fusible element pressure relieving valve hereinafter described. An L 31 is positioned on the fitting 34 and forms a protectiv hood for the exposed opening 36A of the air tubing 36, the L 31 communicates directly with the atmosphere, and forms the exhaust to atmosphere IS.

The plug and connector 35 positioned in the fitting 32 have attached thereto a junction box 38 which serves as a connection box. The plug and connector 35 form means of passing a section of secondary air tubing 39 from th junction box into the interior of the fitting 32. The exterior of the said air tubing 39 is sealed with respect to the plug and connector 35. The air tubing 39 extends through the nipple 30 into the fitting 40 which is affixed to the interior end of the nipple 30. The air tubing 39 leaves the fitting 40 through a seal at a point 4| and communicates with a pressure generating heat actuated device such as is illustrated in Figure 5. The secondary air tubing 39 is protected by a metal conduit 42. It will thus be apparent that the several fittings and parts comprising the assembly illustrated in Figure 2 serve as an efiicient means of establishing three separate and distinct communication channels from the exterior to the interiors of the heat actuating devices within the tank-like enclosure ID. These are; the communication channels defined by the communication tubing 33; the communication channel defined by the air tubing 36 and; the communication channel defined by the secondary air tubing 39. It will be seen that the communication channel defined by the communication tubing 33 extends into the tanklike enclosure [0 by way of the nipple 30 and the fitting 40. It is continued by an air tight protective conduit 43 which encloses the air tubing 36 which, as has heretofore been described, communicates directly with a fixed temperature fusible element pressure relieving valve such as is illustrated in Figure 4 of the drawings,

By referring now to Figure 4 of the drawings, the air tubing 36 enclosed in the protective air tight conduit 43 may be seen to communicate with a T fitting l4, the air tubing 36 entering the T fitting l4 and terminating in a tubing end plug 44 which establishes communication with a section of secondary air tubing 45 which in turn establishes communication with a secondary tubing end plug 46 which establishes communica tion with an air valve body 41. which in effect forms a portion of the T fitting [4. The interior of the air valve body 41 is sealed with respect to the interior of the T fitting M by means of a metal foil seal 48 which is held in position by means of a cylindrical threaded ring 49. The seal 48 is adapted to be broken by means of a spring tensioned rod 50. the spring tension being supplied by a coil spring which opposes a shoulder 41A formed on the interior of the air valve body 41 and a flange 52 formed on an enlarged end 53 of the rod 50, The enlarged end 53 of the rod 50 is positioned within a cylindrical body portion 54 of an automatic sprinkler head 55 and directly against a cap 55 thereof. The flange 52 on the enlarged end 53 of the rod 50 forms a seal with respect to the body portion 54 and prevents communication between the interior of the tank and the interior of the valve body 41. The cylindrical body portion 54 is threaded into the air valve body 41. The cap 56 is held in position on the cylindrical body54 by a pair of sprinkler head arms 51 which in turn are held in operative position at their outermost ends by means of a fusible link 58. It will thus be observed that the communication channel defined by the protective conduit 43, which communicates directly with the communication tubing 33 which in turn communicates directly with the interior of the deluge valve actuation mechanism l1, normally terminates within the T fitting l4, it being effectively separated from the interior of the air valve body 41 by the unbroken metal foil seal 48. The communication channel defined by the air tubing 36 which, as has heretofore been described, is in communication with the atmosphere through L 31 at l8, outside of the enclosure defined by the tank l0, terminates within the air valve body 41, on the other side of the normally unbroken metal foil seal 48. The purpose of the entire device illustrated in Figure 4 is to cause, upon the fusing of the fusible element 58, the rupture of the metal foil seal 48 which is accomplished by the arms 51 of the sprinkler head moving apart upon the fusing of the fusible element 53 which action releases the cap 56 and permits the rod 50 to be moved by the coil spring 5|. As the rod 59 is attached to the metal foil seal 48, the same is immediately ruptured and a clear and distinct air passageway is established between the interior of the T fitting l4 and the interior of the air valve body 41. Due to this rupture, pressure above atmospheric maintained by suitable means in the valve actuating mechanism housing I1 heretofore described is relieved by way of the air tubing and 36 which as has heretofore been described communicates with the atmosphere outside the enclosure defined by the tank In by way of the L 31. When this occurs, the pressure above atmospheric within the secondary air tubing 39, which has heretofore been equal to that in the housing 11, moves the diaphragm ISA causing the pin 20 to move the restraining element 2| which in turn permits the tiltable latch member 23 to tilt and thus directly result in the opening of the deluge valve and the subsequent delivery of fire extinguishing fluid by the sprinkler system.

By referring now to Figure 5 of the drawings, the pressure generating heat actuated device l5 ill] Search Room may be seen, which device comprises a semispherical metal shell 59 in communication with air tubing 39A which forms a part of the pressure generating heat actuated device and which is in direct communication with the air tubing 39 heretofore described. The air tubing 39 is also shown in Figure 3 of the drawings as entering the sprinkler valve actuating mechanism l1 where it communicates directly with the dia phragm case l8 by way of a vented fitting I 8A. The vented fitting comprises a slow leak which normally serves to equalize pressures other than atmospheric in the housing l1. and the air tubing 39 as well as within the semispherical metallic shell 49 of the pressure generating heat actuated device l5. The pressure generating heat actuated device is not further described and illustrated as the same is well known in the art; comprising a portion of the disclosure of U. S. Patent No. 2,099,069 of November 16, 1937 to E. A. Lowe et al. on Fire extinguishing and alarm apparatus.

By referring now to Figure 6 of the drawings, a modification comprising an adaption of the fixed temperature fusible element pressure relieving valve for use in a material conveying duet may be seen. The device of the modification operates in the same manner as the device heretofore described and illustrated in Figure 4 with the exception that the communication channel to atmosphere is directly to the exterior of the duct. In Figure 6 an air tube communicates with the interior of the valve actuating mechanism l1 and therefore forms a counter-part of the tube 43 described in connection with Figure 4 of the drawings. A coupling 6| provides a mounting for an air valve body 62, a counter-part of the air valve body 41 heretofore described, and serves to enclose a metal foil seal; a rod for rupturing the same and a spring for moving the rod, all exactly the same as that heretofore described in connection with Figure 4, and which are subject to release by means of a conventional automatic sprinkler head 63 such as heretofore described. In the modification in Figure 6, the air pressure other than atmospheric normally confined to the air tube 60 is placed in communication, upon the rupture of the metal foil seal, with a tube end plug 64 which in turn communicates with a short section of air tubing 65 which passes through the duct, indicated by the numeral 66, in an air tight manner, and terminates with the outer end of the air tube in open communication with the atmosphere. In operation, the device of the modification will, upon the fusing of the automatic sprinkler head, result in the rupture of the metal foil seal and permit the pressure above atmospheric in air tube to be released to the at mosphere through the air tubing 65. This, as has heretofore been explained, results in the unequalization of pressures within the valve actuating mechanism enclosing housing 11 which results directly in the movement of the diaphragm ISA and subsequent tripping of the deluge valve and opening of the same.

In the operation of the devices described so far, it is apparent that either one of two heat detecting actions result in the movement of the diaphragm ISA and the immediate opening of the deluge valve indirectly operated thereby. These actions have exactly the same results; one originating as a pneumatic impulse in the semispherical metal shell 59 of the pressure generating heat actuated device l5 directly moves the diaphragm 19A as the increased pressure momentarily overcomes the balance normally maintained by the vent "IA. The other action lowers the pressure other than atmospheric in the housing I1 and exactly the same result occurs as the pressure within the pressure generating heat actuated device l and the connecting tube is therefore greater than that in the housing H, the diaphragm 19A moves and trips the mechanism and causes the deluge valve actuated thereby to open. The diaphragm I9A always moves in one direction, toward the bowed wall and the pin 20, regardless of which of the two actions takes place. The result in either event is the extremely prompt opening of the deluge valve and the subsequent action of the deluge sprinkler system.

Further modifications of the invention are desirable particularly at such times as the devices are installed in tanks or other enclosures in which inflammables or explosive materials are placed and which tanks, unlike the solvent recovery tanks heretofore referred to, are open to the atmosphere to an extent to preclude the building up of pressin'es above atmospheric therein. It is therefore possible to form the invention so that pressure other than atmospheric in the valve actuating mechanism housing II is released directly into the tank or other enclosure when the heat actuated devices operate.

By referring to Figure 7 of the drawings, a wall of the tank-like enclosure, wherein pressures are the same as atmospheric, is indicated by the numeral 61. A nipple 68 is passed through an opening in the wall 6'! and re-enforcing members 69 are supplied to insure the adequate support thereabout. A T fitting Ill is positioned upon the outermost end of the nipple 68 and a communicating tube 'II is placed in communication therewith, the outer end of the communicating tube 'Il being placed in communication with the valve actuating mechanism housing 11 in exactly the same manner as the tubing 33 heretofore described in connection with Figure 2. Pressures other than atmospheric maintained by suitable means in the valve actuating mechanism housing I! are therefore brought into direct communication with the T fitting III, the nipple 68 and into a union I2 located on the innermost end of the nipple 63. An air tube I3 in communication with the union I2 continues the communication channel to a secondary T fitting I4 which serves as a mounting for a normally closed automatic sprinkler head I5. The pressure above atmosphe maintained in the valve actuating mechanism housing I1 is thereby in direct communication with the interior of the secondary T fitting 14 and subject to relief upon the fusing of the automatic sprinkler head I5. When this occurs, the loss of pressure above atmospheric within the valve actuating mechanism housing I I results in the movement of the diaphragm ISA as has been heretofore described, which movement causes the opening of the deluge valve.

The other one of the dual heat actuated devices comprises a pressure generating heat actuated device I6 exactly the same as that illustrated in Figure 5 and heretofore described. A semispherical metal shell 'I'I communicates by way of an air tube I8, with the diaphragm case I9 in the valve actuating mechanism housing il in exactly the same manner as the air tubing 39 heretofore illustrated and described in connection with Figure 2. The air tube 18 enters the secondary fitting 14 by way of a plug and connector I9 the plug portion of which is threadably 15 engaged in the secondary T fitting I4. The exterior of the air tubing I8 is sealed to the interior of the plug and connector I9. A similar plug and connector also sealed to the exterior of the air tube I8 is threadably engaged in the T fitting I0 and serves to pass the air tube 18 out of the communication channel defined by the fitting l0 and the air tube I3 heretofore described. The air tube I8 upon emerging from the plug and connector 80, enters a junction box 8| from whence the air tube I8 continues to the diaphragm case I9 within the valve actuating mechanism housing II in exactly the same manher as the air tube 39 heretofore described.

Pressure generated by the rapid rise of temperature about the semispherical metal shell II of the pressure generating heat actuated device I6 is thereby conveyed directly to the diaphragm case I9 where it serves to move the diaphragm ISA which action results in the opening of the deluge valve of the sprinkler system. The operation of this modified form of the invention is exactly the same as the form of the invention heretofore described. The modification must, however, necessarily be installed in enclosures wherein the pressures are atmospheric or below, so that pressures above atmospheric maintained in the valve actuating mechanism housing I! and the communicating parts of the system can be reduced by opening the system. This form of the invention is therefore designed for operation in enclosures where normal pressures are atmospheric.

The provision of dual means for insuring the actuation of the deluge sprinkler valve of the sprinkler system, the device of the invention, has been made to insure the positive going into operation of the deluge sprinkler system as the hazardous locations in which the device of the invention is installed make it imperative that exceedingly prompt and dependable action result upon the outbreak of a fire or the existence of conditions likely to result in a fire or explosion. The device of the invention is relatively simple and therefore extremely dependable and its dual heat detecting devices insure its positive operation regardless of the locations in which it may be installed.

Having thus described my invention, what I claim is:

1. The combination of a tank-like enclosure adapted to confine pressures in excess of atmos pheric, a sprinkler system incorporating valve actuating mechanism; and a pair of heat actuated devices positioned within the tank-like enclosure, means establishing communication between the said heat actuated devices and the said valve actuating mechanism and between one of the said heat actuated devices and the exterior of the said tank-like enclosure, said valve actuating mechanism, the heat actuated devices and the communication means between the said heat actuated devices and the said actuating mechanism normally containing air at a pressure in excess of atmospheric, one of the said heat actuated devices adapted to generate a pneumatic impulse and the other one of the said heat actuated devices adapted to relieve the pressure normally maintained in the said heat actuated devices and actuating mechanism, the said relief of pressure being by way of the said communication channel to the exterior of the said tanklike enclosure so that pressure in the tank-like enclosure will not interfere therewith, the said 103. Hill. LA i INUUISHERS,

actuating mechanism being responsive to either pneumatic action.

2. The combination of an enclosure wherein pressures in excess of atmospheric are normal, a fire extinguishing system therefore, including a sprinkler valve actuating mechanism; and a pair of heat actuated devices positioned within the enclosure, means establishing communication between the said heat actuated devices and the said actuating mechanism and secondary communication means establishing communication between one of the said heat actuated devices and the exterior of the said enclosure, the first mentioned communication means, the actuating mechanism, and the heat actuated devices normally containing air at a pressure in excess of atmospheric, one of the said heat actuated devices comprising a pressure generating device and the other one of the heat actuating devices comprising a pressure relieving device, the said sprinkler valve actuating mechanism responsive to either one of the said pneumatic actions.

3. The combination of a tank-like enclosure wherein pressures in excess of atmospheric are normal, a fire extinguishing system therefore including distributing pipes therein, a sprinkler valve having a valve actuating mechanism therefore; and a pair of heat actuated devices positioned within the said enclosure, one of the heat actuated devices comprising a pressure generating device, means of communication between the said pressure generating device and a portion of the said actuating mechanism, the other one of the said heat actuated devices comprising a fixed temperature fusible element controlled valve positioned in and controlling a communication member, one end of which communicates with a portion of the said valve actuating mechanism and the other end of which communicates with the exterior of the said enclosure, the said pressure generating heat actuated device, its means of communication, th valve actuating mechanism, and the portion of the communicating member extending between the valve actuating mechanism and the pressure relieving heat actuated device normally containing air at a pressure in excess of atmospheric.

4. The combination of a tank-like enclosure wherein pressures in excess of atmospheric are normal, a fire extinguishing system therefore including distributing pipes therein, a sprinkler valve having a valve actuating mechanism therefore; and a pair of heat actuated devices positioned within the said enclosure, one of the heat actuated devices comprising a pressure generating device, means of communication between the said pressure generating device and a portion of the said actuating mechanism, the other one of the said heat actuated devices comprising a fixed temperature fusible element controlled valve positioned in and controlling a communication member, one end of which communicates with a portion of the said valve actuating mechanism and the other end of which communicates with the exterior of the said enclosure, the valve actuating mechanism and th portion of the communicating member extending between the valve actuating mechanism and the pressure relieving heat actuated device normally containing air at a pressure in excess of atmospheric.

5. The combination of an enclosure wherein pressures in excess of atmospheric are normal; and a sprinkler valve actuating device comprising a sprinkler valve actuating mechanism hav Searcn 00W ing a heat actuated device, communication means between said valve actuating device and said heat actuated device, the said heat actuated device positioned within the said enclosure, the said heat actuated device and the said communication means normally containing air at a pressure in excess of atmospheric, the said heat actuated device comprising a pressure relieving device, the said actuating mechanism adapted to be actuated by relief of the pressure normally maintained therein, a secondary communication means in communication with the said pressure relieving heat actuated device and in communication with the exterior of th said enclosure so that pressure relieved by the said heat actuated device exhausts to atmosphere therethrough and the operation is unaffected by the pressure in the tank-like enclosure.

6. In a heat detecting system, the combination of an enclosure and dual heat detecting devices therein, means of communication extending between the said dual heat detecting devices and the exterior of the said enclosure, the said dual heat detecting devices and the said communication means normally containing air at a pressure in excess of atmospheric, one of the said dual heat detecting devices comprising a pressure generating device and the other one of the said dual heat detecting devices comprising a pressure relieving device, a secondary communication means in communication with the said pressure relieving heat detecting device and in communication with the exterior of the said enclosure so that pressure relieved by the said heat detecting device upon actuation exhausts to atmosphere therethrough.

7. The combination of a fire extinguishing system and an enclosure in which the distributing piping of the system is located, a main pressure responsive device for operating the said system, dual heat detecting devices in the enclosure, and means of communication extending from each of the said heat detecting devices to the said pressure responsive device, one of the said dual heat detecting devices comprising a pressure producing device and the other one comprising a pressure relieving device, the said main pressure responsive device including means normally equalizing pressures between the dual heat detecting devices and their dual communication means, the said pressure responsive device responsive to either a reduction of pressure or an increase of pressure as caused by the said dual heat detecting devices, a secondary means of communication extending from the said pressure relieving heat detecting device to the exterior of the said enclosure so that pressures relieved by the said pressure relieving heat detecting device may be exhausted to the exterior of the enclosure.

8. The combination of a tank-like enclosure and a fire controlling apparatus therefore, the said fire controlling apparatus including actuating means comprising a pressure responsive means responsive to either an increase or decrease of pressure for bringing said fire controlling apparatus into operation, a sealed heat responsive unit in the said enclosure adapted to cause an increase of pressure when heated and communicating with the said pressure responsive means, a secondary sealed heat responsive pressure relieving unit in the enclosure adapted to relieve pressure confined thereby when heated and communicating with said pressure responsive means, the said pressure responsive means including means for slowly equalizing pressures between the said sealed heat responsive unit and secondary sealed heat responsive pressure relieving unit so that the unbalancing of the said pressures therein as caused by the increase of pressure originated by the sealed heat responsive unit or the decrease caused by the secondary sealed heat responsive pressure relieving unit may be employed to actuate the said pressure responsive means, a secondary means of communication in communication with the said secondary sealed heat responsive pressure relieving unit and extending to the exterior of the said tank-like enclosure so that pressure relieved by the said secondary sealed heat responsive pressure relieving unit is exhausted to atmosphere therethrough.

HARRY N. RIDER. 

